59 research outputs found
PENYULINGAN AIR LAUT MENJADI AIR TAWAR
Get PDFAbstrak: Penyulingan air laut menjadi air tawar adalah proses untuk mendapatkan air bersih bagi masyarakat pesisirpantai. Hasil lain dari penyulingan air laut adalah garam. Disini diuji suatu peralatan penyulingan air laut untukmendapatkan air tawar sekaligus garam yang terbentuk saat penyulingan. Alat penyuling dibuat sederhana denganmenggunakan bahan bakar LPG sebagai sumber panas untuk penguapan. Jumlah air laut yang di uji dalam penelitian inisebanyak 4 liter, masing-masing 1 liter untuk 4 kali pengujian. Dari hasil pengujian rata-rata air tawar yang dapatdisuling sebanyak 814,5 ml air bersih, garam sebanyak 34,75 gr. Waktu pendidihan rata-rata 13 menit, jumlah bahanbakar yang dipergunakan setiap pengujian rata rata 190 gr setara energi sebesar 1530,329 Watt, jumlah panas untukpendidihan hingga penguapan setara dengan1020.139 Watt dan waktu yang diperlukan untuk penguapan sampai habisadalah 2 jam 12 menit. Efisiensi alat penyuling sebesar 66.6 %.Kata kunci: penyulingan, air laut, air tawar dan garam dapu
On breathers in affine toda theories
Get PDFOscillating solitonic solutions, the breathers, of affine Toda theory are studied. These breather solutions are constructed from two solitons of the same mass with velocity opposite of each other; by analytically continuing its velocity or rapidity to a complex value, the resulting solution becomes a periodic solution. Generally, the parameters in the soliton solutions are restricted to a certain range of definition. In particular, it is shown for a(^(1))(_n) and d(^(1))(_4) cases, these restrictions can be calculated explicitly. To some cases of a(^(a))(_n) theories, one can show that there are sine-Gordon embedded solitons which give rise to a sine-Gordon breather. Furthermore, these breather solutions carry topological charges. These topological charges are calculated and it is found that they are exactly the same as the topological charges of some single soliton cases. Moreover, for the non-zero topological charges, one can show they belong to the irreducible fundamental representation component of the tensor product of two fundamental representations associated with the constituent solitons. This Clebsch-Gordan decomposition property is in agreement with the fusing rule of soliton which in turn is similar to the fusing rule of the fundamental Toda particles. One can also make a conjecture that the zero topological charge is always carried by a breather whose constituent solitons are associated with either conjugate or self-conjugate fundamental representations. Although it is not possible to know the individual topological charge carried by the constituent solitons in a breather, nevertheless using the crossing symmetry similar to that of the crossing symmetry of the S'-matrix, one can perform a superficial calculation to determine the constituent soliton's topological charges. Attempts to understand the exact scattering matrices of the sine-Gordon solitons and breathers from a root space point of . view is also discussed. This study tries to mimic the exact S-matrix construction of the real coupling regime affine Toda theory from the root space by Dorey. In this study, one replaces the ordinary Coxeter element, which plays an important role in the real coupling regime, with other transformations to incorporate the infinite product nature of the sine-Gordon soliton scattering matrix. However, the desired consistent construction seems to elude the author in this study
The Thermal Interference Effect of Neighbouring Geothermal License Areas: a Parameter Modelling Study
No full textIn a future scenario, the successful development of geothermal industry will result in the large-scale deployment of new deep geothermal projects. In highly populated areas, such as the Netherlands, such a development will lead to a dense grid of neighbouring licenses. In such a situation a new project requires careful design and planning as the available subsurface space can become scarce, leading to the potential thermal interference with the neighbouring licenses and competing usage of the resources. Interference can cause the reduction of lifetime, produced energy, and the profitability of neighbouring projects. Therefore, it becomes important to consider the thermal interference while designing these systems in such dense areas to be able to obtain maximum energy and profit without hindering neighbours. This research project assesses the question of thermal interferences in neighbouring geothermal systems using a numerical simulation approach regarding what parameters are ideal for optimisation in neighbouring systems and what parameters should be monitored. To generate a numerical model capable of describing and predicting the effect of thermal interference the software package COMSOL Multiphysics 5.4 was used. The physics of fluid flow and heat transfer in porous media is applied to the reservoir model, and the finite element method is used to approximate the solution of these equations. Sensitivity analyses are performed on all input parameters as a post-processed simulation to control their influence on the output performance. The input parameters are divided into two categories; first, operational-controlled parameters: start time, injection temperature, injection/production flow rate, well spacing, well distance to the license border, and second, natural-controlled parameters including permeability and its anisotropy as kx/ky ratio. At the end of the parametric sensitivity analysis, an economic model is used as an instrument to evaluate how these input parameters can affect the long-term project feasibility. In this study, we present the results of global comparisons between each parameter while incorporating all measurement control (lifetime, cumulative energy and NPV). The results from the 3D qualification, the correlation between measurement controls and the reference base case study are used as background for this comparison. Our results show that the injection temperature and well spacing are ideal designed parameters to optimise profitability because the negative effect on the neighbour is only 1% for every 10°C reduction injection temperature and increasing 300 m of well spacing. On the other hand, injection / production flow rate is the most influential parameter that must be monitored in neighbouring production areas.Petroleum Engineering and Geo-science
Design of a Magnetic Bearing Levitation System to Increase DC Motor Efficiency Using the Halbach Array Method
No full textBearings are machine elements that function to support loads when two machine elements move relative to each other. Every object that moves relatively will definitely cause friction. Any friction that occurs will definitely cause wear which will affect the service life of the element. In conventional bearings, ball bearings are used to reduce friction losses so that they can reduce mechanical losses and can maximize the net output of rotation in DC motors. Magnetic levitation bearing technology will produce a lifting force that hovers over the rotor by utilizing the repulsion of magnetic poles. Very low coefficient of friction, in addition magnetic bearings do not require additional power for the control system and do not require lubricating fluid supply or disposal. The author anticipates axial instability by using the Halbach array method. This method can produce an increase in the magnetic field on one side of the array by canceling the magnetic field on the other side until it approaches zero. This method will produce a spatially rotating magnetization pattern. In this research the author will design a magnetic levitation bearing using N52 Neodymium permanent magnets with the Halbach array method in a permanent magnet configuration. Based on the results of the analysis in this study, the use of magnetic levitation bearings using the Halbach array method can reduce mechanical losses thereby increasing the efficiency of the DC motor by 4,23% and can reduce the temperature of a DC motor when operating by 1,78%.66 PagesSkripsi Sarjan
Development of a spark plug fuel injector for direct injection of natural ags in spark ignition engine
Get PDFIn the name of God, The Most Gracious, The Most Merciful. By His will, this thesis has
been completed as another episode of knowledge seeking and contribution.
The author wishes to express a greatest gratitude to the academic supervisor for this project,
Dr. Matthew Harrison and Professor Douglas Greenhalgh for their warmth, continuous
guidance and support, priceless knowledge and expertise, and kindly understanding.
Secondly, author's deepest appreciation to Dr. Mark Jermy, the initial supervisor for this
project, for his ideas, understanding, support, availability and generosity for providing
assistance both in author's academic and private life.
To my mother and father whose supplications and encouragements have given me strength
to complete this work. To my family whose support during this course of studies has given
me comfort. To my parents in-law and siblings in-law, thank you for your support.
My dearest gratitude to the beloved wife, Ira for standing by my side and giving me
continuous support throughout this course of study and the hardship of life due to it. Your
sacrifice is priceless. To my children, Balgis, Naufal, Nadiyah and Safiyah, you are my source
of inspirations.
A special thank to Dr. Glenn Sherwood, Tim Lee, Brian Scully, Richard Kennewell, Alan
Hutching, and all others for providing technical supports during the experiment works.
To Andreas, Eudoxios, Anni, Edouard, Fatiha, Alessio, Andy and Adam, I thank you all for
the friendship and helps during my studies
The History of "Tuan Seberang" (Tun Seri Lanang) Based on Aceh and Dutch Sources
No full textThis study discusses the position of Tuan Seberang, a prominent figure of the Malay Peninsula, who was immensely influential in shaping the kingdom of Aceh Darussalam in the 17th century. His prominence was evident when the book of Aceh's historiography, Ma Bain-as-Salatin, clearly showed the position of and role played by Tuan Seberang in the administration of this kingdom. However, to date, there are rarely historians who have actually examines the position and prominence of Tuan Seberang, either when he was in Aceh or in the Peninsula. To be sure, Tuan Seberang was a prominent figure who was highly respected by the Portuguese and Dutch because of his huge contribution to the administration of this kingdom during the reign of Sultan Iskandar Muda (1607-1636), Sultan Iskandar Thani (1636-1641) and Sultan Safiatuddin Syah (1641-1675). In this study, the author examines the issue of who Tuan Seberang really was, the role he played, his contribution and his relationship with the rulers and Aceh's political figures.
Keywords: Tuan Seberang, Tun Seri Lanang, Sulalat-us-Salatin, Ma Bain-as-Salatin, The Kingdom of Aceh DarussalamKajian ini membincangkan tentang kedudukan Tuan Seberang, tokoh Melayu Semenanjung, yang sangat berpengaruh dalam perkembangan kerajaan Aceh Darussalam pada kurun ke-17. Ketokohannya terbukti apabila karya historiografi Aceh, Ma Bain-as-Salatin dengan jelas memerihalkan kedudukan dan peranan yang dimainkan oleh Tuan Seberang dalam pentadbiran kerajaan itu. Namun sehingga kini, jarang terdapat ahli sejarah yang benar-benar meneliti kedudukan dan peranan Tuan Seberang secara khusus, sama ada semasa beliau berada di Aceh atau di Semenanjung. Padahal Tuan Seberang merupakan seorang tokoh terkemuka yang sangat dihormati oleh Portugis dan Belanda kerana sumbangan besarnya kepada pentadbiran kerajaan tersebut semasa pemerintahan Sultan Iskandar Muda (1607-1636), Sultan Iskandar Thani (1636-1641 ) dan Sultan Safiatuddin Syah (1641-1675). Dalam kajian ini, penulis meneliti tentang persoalan siapa sebenarnya Tuan Seberang dalam sejarah Aceh, peranan dan sumbangannya serta hubungannya dengan para pemerintah dan tokoh politik Aceh.
Kata kunci: Tuan Seberang, Tun Seri Lanang, Sulalat-us-Salatin, Ma Bain-as-Salatin, Kerajaan Aceh Darussala
Efficient finite element modelling for the investigation of the dynamic behaviour of a structure with bolted joints
No full textBurnscar analysis using normalized burning ratio (NBR) index during 2015 forest fire at Merang-Kepahyang peat forest, South Sumatra, Indonesia
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